Plugin: Only apply the viewScript compat to core blocks

[dd32]

See #45870

What?

This PR limits the functionality in gutenberg_block_type_metadata_multiple_view_scripts() to gutenberg-provided blocks only.

Why?

This is done as gutenberg_block_type_metadata_multiple_view_scripts() relies upon gutenberg_block_type_metadata_view_script() which only operates on files present within Gutenberg.

As noted within #45870 this causes WordPress 6.1 + Gutenberg plugin to be unable to use a block which has multiple items in the viewScript property.

How?

The exclusion logic from gutenberg_block_type_metadata_view_script() is copied to gutenberg_block_type_metadata_multiple_view_scripts().

This ensures that any viewScripts that are from plugin-provided blocks fall through to the Core support.

Testing Instructions

1. Add a block with viewScript: [ "file:./index.js", "registered-script-handle", "script-handle-two" ]
2. View the front-end page source with that block present. All three handles should be present.

Testing Instructions for Keyboard

Screenshots or screencast

[gziolo]

I left a comment in the issue #45870 (comment). The gist of it is we should move this updated hook to provide back compat only as long as we support WP 6.0.

[gziolo]

I left a comment in the issue #45870 (comment). The gist of it is we should move this updated hook to provide back compat only as long as we support WP 6.0.

It looks like we will drop support for WordPress 6.0 with #48268. I think we can close this PR now, as the alternative completely removes the custom handling in the Gutenberg plugin.